Portable radios vastly improve the effectiveness of police, fire and military personnel. During a public or military emergency, often the first personnel on-site can avert tragedy and can direct subsequent personnel as to how to best respond to the exigencies of the situation.
However, the first personnel on-site can become injured by unstable situations. For example, during a fire, firemen can become lost in smoke filled buildings while looking for fire victims. If not found, fireman can become overcome by the smoke with fatal results.
Similarly, in covert operations by the military, hostile fire can incapacitate personnel during an initial or unintended contact with hostile forces. If incapacitated personnel cannot be quickly located, the result, again, can be fatal.
In general, methods of locating personnel (via their transceiver) are known. For example, cellular base stations typically hand off cell phones among base stations based upon a received signal strength indication (RSSI). In such cases, RSSI is assumed to be a measure of distance from the base station. By knowing the distance from the base station, a controller of the base stations may determine a location of the cell phone to within a few hundred feet.
On the other hand, where the transceiver is carried by a fireman within a building, the determination of location within a few hundred feet may not be sufficiently accurate, especially where the entire building may only be a few hundred feet on a side. Accordingly, a need exists for a method of locating public service or military radios that is more accurate than prior methods.